Character ... is the first character of a delimiter but occurred as data
Cause:
This message may appear in several cases:
- You tried to include the "<" character in your page: you should escape it as "<"</li>
- You used an unescaped ampersand "&": this may be valid in some contexts, but it is recommended to use "&", which is always safe.
- Another possibility is that you forgot to close quotes in a previous tag.
Example:
 | <p>The first character of an HTML element is <</p> |
 | <p>The first character of an HTML element is <</p> |
Solution:
Replace the character with a proper Character Entity.
References: